/*
 * Copyright [2021-present] [ahoo wang <ahoowang@qq.com> (https://github.com/Ahoo-Wang)].
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *      http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package me.ahoo.wow.messaging.propagation

import me.ahoo.wow.api.messaging.Header
import me.ahoo.wow.api.messaging.Message
import me.ahoo.wow.command.wait.extractWaitStrategy

/**
 * Propagator that handles wait strategy propagation from upstream messages.
 *
 * This propagator extracts wait strategy information from upstream headers
 * and delegates the actual propagation to the wait strategy implementation.
 */
class WaitStrategyMessagePropagator : MessagePropagator {
    /**
     * Propagates wait strategy information from the upstream message.
     *
     * If no wait strategy is present in the upstream header, this method returns early.
     *
     * @param header The target header to propagate to
     * @param upstream The upstream message to propagate from
     */
    override fun propagate(
        header: Header,
        upstream: Message<*, *>
    ) {
        val upstreamHeader = upstream.header
        val waitStrategy = upstreamHeader.extractWaitStrategy() ?: return
        waitStrategy.propagate(header, upstream)
    }
}
